Rhodium-catalyzed oxidative benzannulation of N-adamantyl-1-naphthylamines with internal alkynes to produce highly substituted anthracenes in satisfactory to good yields was developed. The annulation reaction proceeded smoothly under mild conditions in the presence of [Cp*RhCl2]2 as the precatalyst and Cu(OAc)2 as the oxidant.

A new halogenation method to construct halogen-substituted quinoline moieties is described. The Cu-catalyzed intramolecular aza-Diels–Alder reaction and halogenation reaction proceeded smoothly under mild conditions to produce the corresponding 7-chloro-6H-chromeno[4,3-b]quinolines and 7-chloro-6H-thiochromeno[4,3-b]quinolines in satisfactory yields.

An efficient method for the synthesis of isoquinolones through base KOtBu-promoted SNAr reaction of 2-halobenzonitriles with ketones followed by Lewis acid Cu(OAc)2-catalyzed cyclization is described. Isoquinolone derivatives were obtained in satisfactory to good yields.

Brønsted acid catalyzed cyclization reactions of 2-amino thiophenols/anilines with β-diketones under oxidant-, metal-, and radiation-free conditions are described. Various 2-substituted benzothiazoles/benzimidazoles are obtained in satisfactory to excellent yields. Different groups such as methyl, chloro, nitro, and methoxy linked on benzene rings were tolerated under the optimized reaction conditions.

•Three organic dyes with different fluorene-derived π-conjugated bridges were applied in dye-sensitized solar cells.•The alkyl group is better than aryl group in D–π–A dye to avoid the π–π aggregation.•The device based on sensitizer F3 achieved an efficiency of 5.15% was measured for a solar cell device.New metal-free organic sensitizers containing a fluorene unit as a π-conjugated system, a diphenylamine as an electron donor, and a cyanoacrylic acid moiety as an electron acceptor were synthesized and used for dye-sensitized solar cells. The photophysical and electrochemical properties of these dyes were investigated, and their performances as sensitizers in solar cells were measured. One solar cell containing the n-hexyl group in the fluorene unit produced an η of 5.15% (Jsc = 9.69 mA cm−2, Voc = 0.77 V, and ff = 0.70) under 100 mW cm−2 simulated AM 1.5 G solar irradiation (100 mW cm−2).

•Five organic dyes with different electron acceptors were applied in dye-sensitized solar cells.•Cyanoacetic acid proved to be the best electron acceptor in D–π–A dye in improving high cell conversion efficiency.•The device based on sensitizer DPC achieved an efficiency of 4.93% was measured for a solar cell device.Five kinds of triphenylamine-based organic dyes with different electron acceptors were designed and synthesized as sensitizers for dye-sensitized solar cells (DSSCs). The photophysical and electrochemical properties of these dyes were investigated and their performance as sensitizers in DSSCs was measured. The dye with cyanoacrylic acid electron acceptor exhibits the highest solar-to-electrical energy conversion efficiency of 4.93% (short-circuit photocurrent density Jsc = 8.59 mA cm−2, open-circuit photovoltage Voc = 0.77 V, and fill factor ff = 0.75) under 100 mW cm−2-simulated AM 1.5 G solar irradiation.

Cyclization reactions of 2-aminophenols with β-diketones catalyzed by a combination of Brønsted acid and CuI are presented. Various 2-substituted benzoxazoles were obtained through these reactions. Different substituents such as methyl, chloro, bromo, nitro, and methoxy on 2-aminophenol are tolerated under the optimized reaction conditions.

An efficient method for the synthesis of enaminones is described. The aldol-type addition of ketones to aromatic nitriles proceeded smoothly in the presence of a simple copper catalyst system (CuI–2,2′-bipyridine–NaOtBu) in N,N-dimethylformamide. Enaminones in satisfactory to excellent yields were produced using this technique.

New metal-free organic sensitizers containing a benzo[d]thiazole or phenyl unit as the π-conjugated system, a triphenylamine as an electron donor, and a cyanoacrylic acid moiety as an electron acceptor were synthesized and used for dye-sensitized solar cells. Photophysical and electrochemical properties of these dyes were investigated, and their performances as sensitizers in solar cells were measured. The introduction of a benzo[d]thiazole unit into the molecular structure resulted in a high incident photon-to-current conversion efficiency (more than 70%) from 340 nm to 600 nm. One solar cell containing a benzo[d]thiazole unit, produced a η of 5.85% (JSC = 10.63 mA cm−2, VOC = 0.72 V, and ff = 0.77) under 100 mW cm−2 simulated AM 1.5 G solar irradiation.Graphical abstractHighlights► Three organic dyes with different π-conjugated bridges were applied in dye-sensitized solar cells. ► The benzo[d]thiazole unit was introduced into D–π–A organic sensitizer to inhibit aggregation. ► The device based on sensitizer DBT1 achieved an efficiency of 5.85% was measured for a solar cell device.

An efficient method for the synthesis of 3,5-disubstituted pyrazoles is described. The reactions of 1,3-dialkynes with hydrazine proceeded smoothly in dimethyl sulfoxide under mild reaction conditions to produce 3,5-disubstituted pyrazoles in satisfactory to excellent yields. A one-pot procedure of the transformation has been developed.

An efficient method for the synthesis of 3,5-disubstituted isoxazoles is described. The reactions of 1,3-dialkynes with hydroxylamine proceeded smoothly in DMSO under mild reaction conditions to produce 3,5-disubstituted isoxazoles in satisfactory to excellent yields.

An efficient method for the synthesis of indolylglycine derivatives is described. The oxidative coupling reactions of ethyl 2-(disubstituted amino)acetates with indoles proceeded smoothly in the presence of meta-chloroperoxybenzoic acid (mCPBA) under ambient conditions to produce indolylglycine derivatives in satisfactory to excellent yields.

An efficient method for synthesizing N,N-dimethylpropargylamines is described. The synthesis exploited the Cu(II)-catalyzed oxidative alkynylation reaction of trimethylamine N-oxides with alkynes in the absence of external oxidant. Both aromatic and aliphatic alkynes were utilized to achieve the corresponding products in moderate to excellent yields. The reaction conditions tolerated ester, hydroxy, and aldehyde groups.

An efficient method for the synthesis of enaminones is described. The aldol-type addition of ketones to aromatic nitriles proceeded smoothly in the presence of a simple copper catalyst system (CuI–2,2′-bipyridine–NaOtBu) in N,N-dimethylformamide. Enaminones in satisfactory to excellent yields were produced using this technique.